pidof: support for omitted %PPID and additional separators

This commit introduces support for special %PPID value that
can be passed to the -o option as a substitution for parent
PID. It also allows users to use two additional separators
for omitted PIDs - colon and semicolon.

2 files changed, 11 insertions, 4 deletions

diff --git a/pidof.1 b/pidof.1
index f2544c8..f49cd23 100644
--- a/pidof.1
+++ b/pidof.1
@@ -44,7 +44,9 @@ the current root directory of processes they do not own.
 Scripts too - this causes the program to also return process id's of
 shells running the named scripts.
 .IP "-o \fIomitpid\fP"
-Tells \fIpidof\fP to omit processes with that process id.
+Tells \fIpidof\fP to omit processes with that process id. The special
+pid \fB%PPID\fP can be used to name the parent process of the \fIpidof\fP
+program, in other words the calling shell or shell script.
 .SH "EXIT STATUS"
 .TP
 .B 0
diff --git a/pidof.c b/pidof.c
index a39a4c0..72344e7 100644
--- a/pidof.c
+++ b/pidof.c
@@ -246,10 +246,15 @@ static void add_to_omit_list (char *input_arg)
 	pid_t omit_pid;
 
 	omit_str = NULL;
-	omit_str = strtok(input_arg, ",");
+	omit_str = strtok(input_arg, ",;:");
 	while (omit_str) {
 
-		omit_pid = strtoul(omit_str, &endptr, 10);
+		if (!strcmp(omit_str,"%PPID")) {  /* keeping this %PPID garbage for backward compatibility only */
+			omit_pid = getppid();     /* ... as it can be replaced with $$ in common shells */
+			endptr = omit_str + sizeof("%PPID") - 1;
+		} else {
+			omit_pid = strtoul(omit_str, &endptr, 10);
+		}
 
 		if (*endptr == '\0') {
 			if (omit_count == omit_size) {
@@ -265,7 +270,7 @@ static void add_to_omit_list (char *input_arg)
 			xwarnx(_("illegal omit pid value (%s)!\n"), omit_str);
 		}
 
-		omit_str = strtok(NULL, ",");
+		omit_str = strtok(NULL, ",;:");
 	}
 }